var id = 2; // Total number of images
var ranimage = new Array(id); // Array to hold the filenames

ranimage[0] = "images/random/pic01.jpg";
ranimage[1] = "images/random/pic02.jpg";
ranimage[2] = "images/random/pic03.jpg";

function choseRandom(range) {
if (Math.random)
return Math.round(Math.random() * (range-1));
else {
var now = new Date();
return (now.getTime() / 1000) % range;
}
}
//
var choice = choseRandom(id);